The invention relates to a rapid coupler. More particularly, the invention relates to a rapid coupler which avoids the separation of the rapid coupler while the pressure of the liquid therein is very large.
Referring to FIGS. 8 and 9, a conventional coupler comprises a main body 10 coupling with an auxiliary coupler 60. The auxiliary coupler 60 has an outer circular groove 70. The main body 10 has a pipe 40, a sleeve 30 enclosing a top portion of the pipe 40, a plurality of metal balls 20 disposed between the sleeve 30 and the circular groove 70, and a compression spring 50 disposed between the sleeve 30 and the pipe 40. However, the liquid in the conventional coupler will flow out of the coupler while the coupler is detached. Two switches 90 should be disposed on the transportation pipe 80 connecting the main body 10 and the transportation pipe 80 connecting the auxiliary coupler 60, respectively. The user has to switch off the switches 90 before detaching the main body 10 and the auxiliary coupler 60. Further, the metal balls 20 will be oxidized after the metal balls 20 contact the liquid such as water or liquid chemicals for a long period of time. Thus the metal balls 20 will be rusted. The rusted metal balls 20 may engage with the auxiliary coupler 60 very tight, so it is very difficult to detach the auxiliary coupler 60 from the main body 10. If the auxiliary coupler 60 is not inserted in the main body 10 tightly, the liquid will flow out of the gap between the main body 10 and the auxiliary coupler 60.